Demography

Oreochromis

Organic matter

Ecology

Bacteria

Algae

Biology

Fish <Actinopterygii>

Predation

Omnivore

Microcystis

Fishery

Botany

Cyanobacteria

Genetics

Population

Sociology

Nutrient

Journal of Fish Biology

The natural food of Oreochromis niloticus from two Ethiopian Rift Valley lakes, Awasa and Zwai, was studied from the stomach contents. The food was analyzed to determine its chemical composition. The major consumed nutrient by the Awasa population was carbohydrate whereas in the Zwai population it was lipid. Microscopic identification revealed that Microcystis sp. and Botryococcus braunii are the dominant algae present in the food of the fishes from Lakes Zwai and Awasa, respectively. Assimilation efficiency of total organic matter is somewhat low, 28.3% for Awasa and 14.7% for Zwai populations. Both populations assimilated protein to a greater extent than other nutrients. In both lakes the quality of the food, expressed as a ratio of digestible protein to digestible energy, is adequate (&gt;4 mg kJ −1 ) for growth, but the Awasa population appears to have higher growth and better condition.

A study on an herbivorous fish, <i>Oreochromis niloticus</i> L., diet and its quality in two Ethiopian Rift Valley lakes, Awasa and Zwai

A study on an herbivorous fish, Oreochromis niloticus L., diet and its quality in two Ethiopian Rift Valley lakes, Awasa and Zwai